A slow moving area of low pressure pushing into our region this weekend will set the stage for the potential of supercell thunderstorms capable of producing dangerous flooding, extremely large hail, damaging winds and possible tornadoes.
 |
| A look at the slow moving low pressure system that is set to roll into Southern Manitoba on saturday with the Severe Thunderstorm coverage risk map. |
The main surface low starts to move into our area on Saturday, bringing a warm front up from the Northern plains of North Dakota into Southern Manitoba.
So what will the atmosphere have available for the Storm's Tomorrow? Looking at Data Provided by Brad from A Weather Moment
- Moisture: Plentiful. Surface dewpoints will be sitting near 20°C across Southern Manitoba, with 850mb dewpoints pushing up towards 15-17°C. This deep layer of moisture will provide plenty of energy for storms to work with.
- Instability: The major inhibition to storms will be a layer of warm air at 700mb. Temperatures will climb to 10-13°C at 700mb on Saturday morning, however cooler air will push in later in the afternoon, helping destabilize the mid-levels. LI values of -8 to -11, combined with CAPE values anywhere from 2500 J/kg to 5500 J/kg are evidence of an extremely unstable atmosphere.
- Shear: With a decent upper-level jet pushing in through the day, most areas across southwest and south-central Manitoba will see bulk shear values increase to 30-40kt by evening.
- Trigger: A warm front draped across Southern Manitoba will be strong enough to initiate convection in the mid-to-late afternoon as the cap begins to erode.
Overall models are having a hard time deciding on the speed of this system, but they agree that it has the potential to produce dangerous supercell thunderstorms capable of producing tornadoes. The greatest difficulty is predicting where they will form, current indications are that the greatest threat for tornadoes will likely occur in a the region from North of grand Forks towards and north of the Canadian Border. This would likely include the Red river Valley and into Winnipeg and North. Although if this turns out to be different SW Manitoba might be under the gun, for tornadoes. So overall here is the Risk Map for Saturday:
 |
| The Latest Storm Prediction Centre Severe Weather Outlook, areas hatched in red indicates the best chance for severe thunderstorms. |
According to Brad "large MCS will likely develop as the whole system lifts northwards overnight, which will continue to provide a severe weather threat in the form of strong winds and large hail. It will push through the RRV by Sunday morning. We may see the threat for another round of thunderstorms on Sunday afternoon, however they are not expected to be severe. Things will finally cool off on Monday as the main upper low moves through and draws in cooler, dryer air from the west.
Good Evening Everyone! So far the NAM has been wrong and has now agreed with the GFS towards a slower moving System. This would mean a greater threat area for tornadoes out in the Eastern section of SW Manitoba into the Western Red River Valley. Along a line north from The USA Border towards Carberry and The Lake Manitoba area. This Threat will shift eastwards in the evening as the storms progress into a nasty line of severe thunderstorms. They will likely contain damaging Winds in excess of 100 km/h, large hail, intense strobe lightning, and the possible tornado or two. This would likely concern EC to issue watches and warnings throughout the day and even night. stay tuned more information will be available later tomorrow.
ReplyDeleteOne more thing I will be out chasing likely on highway 2 or 3, near Glenboro or Holland. So Tweets will be given Live throughout the day on Twitter. Be Sure to Follow @WeatherInThePeg @lovestormsMB @justinhobson85 and @kylepeddle1 as well as me @SouthMBWeather.
Keep safe Everyone and prepare for the worst if all comes together!
This comment has been removed by a blog administrator.
ReplyDeleteFeel Free to keep up to date as the storm situation and forecast unfolds in Manitoba www.robsobsblog.blogspot.ca and at www.aweathermoment.tumblr.com
ReplyDeleteComments will be added on this blog when needed....
Brandon weather Forecast
ReplyDeleteSaturday
Showers with thunderstorms. Risk of a severe thunderstorm in the afternoon. Wind becoming east 30 km/h in the morning then light late in the afternoon. High 29. UV index 3 or moderate.
Saturday night
Partly cloudy. 60 percent chance of showers or thunderstorms in the evening. Wind becoming west 30 km/h late in the evening. Low 11.
Pilot Mound Weather Forecast
Saturday
Showers with thunderstorms. Risk of a severe thunderstorm in the afternoon. Wind becoming east 30 km/h in the morning then light late in the afternoon. High 29. UV index 3 or moderate.
Saturday night
Partly cloudy. 60 percent chance of showers or thunderstorms in the evening. Wind becoming west 30 km/h late in the evening. Low 11.
Emerson Weather forecast
Saturday
Increasing cloudiness. 60 percent chance of showers in the afternoon with risk of a severe thunderstorm. Wind becoming south 30 km/h early in the afternoon. High 31. UV index 3 or moderate.
Saturday night
Mainly cloudy. 60 percent chance of showers in the evening and after midnight with risk of a thunderstorm. Wind south 30 km/h becoming light late in the evening. Wind becoming northwest 20 before morning. Low 15.
Winnipeg Weather Forecast
Saturday
A mix of sun and cloud. Becoming cloudy in the afternoon with 60 percent chance of showers late in the afternoon. Risk of a severe thunderstorm late in the afternoon. Fog patches dissipating early in the morning. Wind becoming southeast 20 km/h early in the afternoon. High 31. UV index 7 or high.
Saturday night
Partly cloudy. 60 percent chance of showers in the evening and after midnight with risk of a severe thunderstorm. Wind south 30 km/h becoming northwest 20 after midnight. Low 17.